The part after vestibule is called nasal cavity. Its inner wall consists of ciliated epithelium, mucous membranes, olfactory cells, blood vessels, nerve endings, oil glands and numerous hairs. Olfactory cells help in receiving olfactory stimuli.
Function: It moistens dry air and cools hot air. Ciliated cells and mucous membranes trap dust and germs. Olfactory cells help in receiving olfactory stimuli.